There are known wireless power supply devices for charging batteries installed in, for example, electric vehicles via a wireless connection between power receiving coils provided in the vehicles and power transmission coils provided on the ground side. A wireless power supply device can efficiently supply electric power by adjusting a relative position between a power transmission coil and a power receiving coil. In association therewith, there is known a parking assist system equipped with a camera for imaging the rear side of a vehicle and assisting in positioning a power transmission coil and a power receiving coil at the time of parking based on an image obtained by the camera (refer to Patent Literature 1).